Cholera toxin



Cholera toxin (CTX) from the bacterium Vibrio cholerae is an oligomeric complex of an enzymatic subunit (chain A) and 5 copies of chain B which bind to the cell surface. The enzymatic subunit has a globular domain (CTA1) and a long helical domain (CTA2). Once the CTX binds to the cell surface, it is internalized, and its CTA1 domain binds to ADP-ribosylation factor 6 (Arf6) enabling its catalytic activity. The images at the left and at the right correspond to the crystal structure of cholera toxin (1xtc).

CTX
1xtc - CTX

CTX A subunit
2a5d, 2a5g – CTX A subunit+hArf6+GTP – human

2a5f - CTX A subunit+hArf6+GTP+NAD

1s5b, 1s5c, 1s5d, 1s5e, 1s5f - CTX A subunit (mutant)

CTX B subunits
1fgb - CTX B subunits

1g8z, 1chp, 1chq - CTX B subunits (mutant)

1rcv, 1rd9, 1rdp, 1rf2, 1pzi, 1pzj, 1pzk, 1efi, 1eef, 1djr, 1eei – CTX B subunits+ galactoside derivatives

1llr, 1jqy, 1jr0, 1fd7, 1md2 - CTX B subunits+BMSC derivatives

1eef - CTX B subunits+PEPG

3chb, 2chb - CTX B subunits+pentasaccharide

1ct1 - CTX B subunits (mutant)+pentasaccharide

1tet – CTX peptide 3+FAB light and heavy chains - mouse